Distribution Of Sterols And Environmental Behavior In Sediments Of Typical Areas In Northern Xinjiang

The study chooses the sediments of lakes in typical areas of the northern Xinjiang as the researchobject to detect the level of sterols, analyze the distribution characteristics and the sources of pollution.Theoretical basis of the behaviours and fates of sterols in the environment were provided and understoodthe local major pollution sources. In addition, the sediment of lakes in Xinjiang as the adsorbent to studythe adsorption behavior of sterols and study the effect of various factors on sterols, then provide reliablescientific basis for drinking water and agricultural water.Nineteen sediment samples are analyzed and studied. The sediment was got from two seasons. Thesamples were ultrasonic extracted, methylene dichloride/methanol was used as solvent. Chromatographiccolumn of silica gel/aluminum oxide were used to purify the extracts. Finally, the concentration levels ofthe8objects were detected by GC-FID and GC-MS.The results show that the sterols were widespread in sediment of lakes in the study areas, theconcentration of total sterols was in1.33μg/g-50.38μg/g, the mean value was11.99μg/g. all the sterolswere detected, and the content of each component was so different. The content of fecal sterols is far lessthan the content of phytosterols. In the region of research, the content of sitosterol was highest inphytosterols with49.32μg/g, the content cholesterol was high in fecal sterols with42.8μg/g. The level ofpollution is higher in Ulunger lake than the Manas lake. In different periods, the content of sterols was inlarger change, no obviously seasonal, the pollution factors were both natural and man-made.Through the principal component analysis, the sterols of lakes can be divided into two maincomponents, the phytosterols and fecal sterols are the mainly parts. The ratios of fecal sterols could revealthat very little of the sediments were non-polluted by sewage. Through the content of phytosterols, it canalso see that the lakes were eutrophic. The adsorption behavior of sterols in sediment suggested that sterolsdistribution coefficients were reduced with the increase of temperature. The rise of salinity increased theadsorption quantity, it was associated with the increased adsorption area of sediment from organic matterforming colloid. As the increase of pH, sediment adsorption of sterol changed little, slightly increased, thestrong alkaline solution is not conducive to the adsorption of sterols. For hydrophobic groups disappearing,the adsorption of sterols on the surface of sediment decreased. Moreover, along with the change of externalfactors, the ratio between sterols did not change largely, it tended to be stable, so it confirmed sterolsabsorption were synchronous at every point and sterols shall be used as the indicator of fecalcontamination.